1. Field of the Invention
The present invention relates to a sustained release pheromone preparation which releases a pheromone substance into the air for controlling vine mealybug (hereinafter also referred to as “VMB”) having lavandulyl senecioate (hereinafter also referred to as “LVSN”) as a pheromone substance through mass trapping or mating disruption and a control method using the preparation.
2. Description of the Related Art
What is important for establishing a control technology of making use of pheromone is sustained release of pheromone from an attracting source in an amount sufficient to attract wild insects with respect to the mass trapping, and is floating of pheromone in an amount sufficient to disrupt the mating in an entire field to be controlled with respect to the mating disruption. Since insect pests generally emerge over a long period of time from spring to autumn, the mass trapping and the mating disruption are made possible by sustained release of a pheromone substance from a sustained release pheromone preparation having the pheromone substance therein throughout the emergence period. Thus, the development of the sustained release pheromone preparation against a target insect pest has become very important for establishing a control technology with the use of pheromone.
A sustained release pheromone dispenser made of a polymer material such as polyethylene, polypropylene or an ethylene-vinyl acetate copolymer containing vinyl acetate units of 20% by weight or less (hereinafter also referred to as “EVA”), each having an average equilibrium swelling ratio at 20° C. of from 2 to 6% by weight, is known as a preparation for continuously releasing a predetermined amount of a pheromone substance for a long period of time (JP 62-195303A). It is also known that a container such as a cap, a small tube, a laminate bag or a capsule has a pheromone substance sealed therein, wherein the container is made of a material having a release-amount-controlling function, such as rubber, polyethylene, polypropylene, an ethylene-vinyl acetate copolymer containing ethylene units of 90% by weight or more, or polyvinyl chloride, where the ethylene units mean the repeating units derived from ethylene monomers (JP 11-069936A).
Among them, polyolefin-based plastics typified by polyethylene are present in various grades with different properties so that a range of their selection is wide and their cost is low because of their broad utility. Further, the polyolefin-based plastics also have excellent moldability, and allow various types of molding such as extrusion molding, film molding, stretching, and injection molding. In addition, due to excellent mechanical strength, particularly excellent mechanical strength at low temperatures, the polyolefin-based plastics are suited for use during a low temperature period or in a low temperature region.
Further, when a pheromone substance is an acetate compound of a linear aliphatic higher alcohol and the acetate compound has a carbon atom number of from 12 to 20 including a carbon atom number of its functional group, a sustained release pheromone preparation comprising a low-density polyethylene membrane allows the pheromone substance to be released from the preparation continuously for a long period of time. Such a preparation is therefore effective against insect pests that emerge for a long period of time (JP 57-009705A).